The historic Venice Ghetto returned to calm early this week after three days of intensive police controls following an unspecified terrorist threat.

“Things seem back to normal today,” Michaela Zanon of the Venice Jewish Museum told JTA. “There are still police on duty, but nothing like over the weekend.”

Venice authorities launched a massive security action on July 11, apparently in response to a tip that the city’s centuries-old Jewish quarter, a popular tourist attraction, could be a terrorist target.

“There was an alert,” Zanon said. “Police were stationed on every street leading into the ghetto and searched every bag anyone was carrying.”

Police stopped tourists and residents alike and checked their identity papers. They also guarded a number of bridges. Meanwhile, police boats patrolled the waters of the canals surrounding the ghetto and divers went into the lagoon to search for bombs.

The measures were maintained until Sunday. During the alert, Venice Mayor Paolo Costa, speaking on Italian state TV, urged residents to go about their business as usual.

The ghetto has been the center of Jewish life in Venice for 500 years.

The area is on the site of an old foundry where Jews were segregated in 1516. It was Europe’s first example of a forced Jewish settlement, and the word “ghetto” is believed to derive from “geto,” the word for foundry in the Venetian dialect.

In addition to the museum, which encompasses several magnificent synagogues in and around the Ghetto Nuovo, the main square of the district, the ghetto is the site of the headquarters of the 500-strong local Jewish community.

There is also a Chabad house and a Chabad yeshiva on Ghetto Nuovo, as well as a Jewish old-age home, a Holocaust memorial and Jewish souvenir shops. A few steps away are a kosher restaurant and the centuries-old synagogue regularly used by the community.

Most Venetian Jews, however, live in other parts of the city, including the mainland suburb of Mestre.

Zanon said that despite the security alert, tour groups and individual tourists continued to visit the museum.

“We were open normally and had the number of visitors we would have expected,” she said.

The security operation came after Italian news media outlets, quoting a government report, said that Islamic militants linked to Al-Qaida had made plans for terrorist attacks in Italy last year and were scouting locations in Venice.

Italy has been at the center of several investigations targeting alleged Al-Qaida operatives or cells.

On July 11, police in Milan arrested eight men for allegedly aiding Al-Qaida by preparing and distributing forged documents.

Security had already been beefed up to some extent in the ghetto since the intifada erupted nearly two years ago.

Police have kept Jewish sites and institutions in Rome under constant armed guard since a Palestinian terrorist attack on the main synagogue in 1982, which killed a child and injured dozens.

Despite news reports that said security measures had also been tightened in Rome over the weekend, Jewish community spokesman Riccardo Pacifici said the situation was normal.